Items are stored or stocked in distribution or fulfillment centers. Shipments of items can be assembled and fulfilled from distribution or fulfillment centers where the items are stored. Items are retrieved or picked from the inventory storage locations within the fulfillment center by workers and are then packed, and shipped. Items in the inventory in the fulfillment center may be stored in one or more locations within the fulfillment center, either together as a group or separately throughout the fulfillment center. Workers in the fulfillment center are tasked with retrieving items from and/or placing items within the fulfillment center at various locations.